Gabapentin is not FDA-approved for depression and has limited evidence supporting its use as a depression treatment. It is officially approved only for nerve pain after shingles (postherpetic neuralgia) and as an add-on therapy for partial seizures in people with epilepsy. Despite this, gabapentin is increasingly prescribed off-label for psychiatric conditions, with depression and anxiety being the most common psychiatric diagnoses among off-label users.
Why Gabapentin Gets Prescribed Off-Label
Gabapentin was originally designed to mimic GABA, a brain chemical that calms nerve activity. It doesn’t actually work on GABA receptors the way scientists initially expected, but it does increase GABA concentrations in the brain and appears to influence calcium channels on nerve cells. These effects can reduce overactive nerve signaling, which is why it works for seizures and nerve pain. The calming quality of the drug led clinicians to experiment with it for mood and anxiety disorders, even though rigorous evidence for those uses hasn’t followed.
A national analysis of outpatient gabapentin prescriptions from 2011 to 2016, published in Psychiatric Services, found that less than 1% of gabapentin prescriptions were for its FDA-approved uses. Among off-label prescriptions, 5.3% listed a depressive disorder and 3.5% listed an anxiety disorder. That gap between evidence and real-world prescribing is significant.
What the Depression Research Actually Shows
The strongest available data on gabapentin for depression comes from a small retrospective chart review of 27 outpatients with treatment-resistant depression. These patients had already been on a standard antidepressant for at least six weeks without adequate improvement, and gabapentin was added on top of their existing medication at an average dose of about 900 mg per day for roughly 15 weeks.
Results were mixed. About 37% of patients showed a meaningful response by the end of the trial. Another 18.5% improved temporarily but couldn’t sustain that improvement. Notably, 55.5% of patients met response criteria for at least four weeks at some point during treatment, suggesting gabapentin may offer short-term relief for some people even when the benefit doesn’t last. But the study was small, uncontrolled, and assessed retrospectively, making it impossible to know how much of the improvement was due to gabapentin versus placebo effect or other factors.
No large, randomized controlled trials have tested gabapentin as a standalone treatment for major depression. That’s a critical gap. Without placebo-controlled data, there’s no reliable way to measure whether gabapentin genuinely lifts depressive symptoms or simply produces sedation and anxiety relief that feels like improvement.
Gabapentin for Bipolar Depression
Some clinicians have tried gabapentin as a mood stabilizer for bipolar disorder, but the evidence here is equally thin. A review by the UK’s National Institute for Health and Care Research identified only four studies on gabapentin for bipolar disorder, and the studies were so different in design and outcomes that their results couldn’t be combined into a meaningful conclusion. The review found insufficient evidence to support gabapentin use in bipolar disorder and recommended that off-label prescribing for psychiatric conditions be avoided given the lack of efficacy data and potential for harm.
The Anxiety Connection
Much of the off-label psychiatric use of gabapentin likely targets anxiety rather than depression directly. The two conditions overlap heavily, and someone prescribed gabapentin for a depressive disorder may actually be getting it for co-occurring anxiety, insomnia, or restlessness. Gabapentin’s sedating properties can ease the physical tension and sleep disruption that accompany depression, which may explain why some patients feel better on it without the drug treating the depression itself.
That said, even the evidence for gabapentin’s anxiety benefits remains inconclusive. A clinical review by Oregon State University’s Drug Use Research program found insufficient evidence for gabapentin’s efficacy in generalized anxiety disorder, panic disorder, and social anxiety disorder, noting that existing support comes mostly from expert opinion, case reports, and small case series rather than rigorous trials.
Side Effects and Mood-Related Risks
Gabapentin commonly causes drowsiness, dizziness, and difficulty thinking clearly. These cognitive effects can be particularly problematic for people already dealing with the mental fog and low energy of depression.
More concerning is a paradoxical risk: gabapentin can worsen mood in some people. The FDA label carries a warning that all anti-seizure drugs, including gabapentin, are associated with increased risk of suicidal thoughts and behavior. The prescribing information specifically notes that patients should be monitored for the emergence or worsening of depression, suicidal ideation, and unusual mood changes. Some people experience agitation, irritability, hostility, or deepening sadness while taking the drug, and these effects can persist even after stopping it.
Gabapentin also amplifies the effects of alcohol and other sedating substances, which matters because alcohol use frequently co-occurs with depression.
How Gabapentin Compares to Standard Antidepressants
Standard antidepressants like SSRIs and SNRIs have decades of large-scale clinical trial data behind them, with well-established response rates, dosing guidelines, and safety profiles for depression. Gabapentin has none of that for mood disorders. The only depression-specific data involves a handful of patients in uncontrolled settings.
If you’re currently taking gabapentin and noticing mood improvements, that experience is real, but it’s worth understanding that the drug hasn’t been validated for this purpose. If you’ve been prescribed gabapentin specifically for depression, it’s reasonable to ask your prescriber about the reasoning, especially whether the target is actually anxiety, insomnia, or nerve pain that’s contributing to your low mood rather than the depression itself. In most cases, gabapentin would be a complement to a primary antidepressant rather than a replacement for one.